Rotary printing machines may deliver a plurality of webs which are to be guided over a folding triangle. Upon folding, it has been found that improper folding and pinching may occur at the inner webs, as they are being folded, thus resulting in improper folding of all the webs which are superposed. Under some conditions, the paper even may tear.
It has previously been proposed to avoid the aforementioned disadvantages--see, for example, German Published Application DE-AS No. 1 141 650--to provide one or more pairs of supply rollers positioned close to the folding triangle or folding funnel, and which contact each other, with the web interposed, in the plane of the folding triangle. Usually, the rollers which are located below the folding triangle or folding funnel or folding former are located beneath the triangle or former, for example in recesses, notches or grooves formed therein. These rollers are driven, preferably with the speed of the uppermost one of the webs. The arrangement is intended to match the speed of the lowermost web to that of the uppermost web. Speed differences between the remaining webs, for example if a plurality of webs greater than two is to be superimposed, cannot, however, be entirely eliminated, and improper folds, pleats, pinched zones, or tears of the intervening webs cannot be avoided by this arrangement.